body {
    margin: 0;
    overflow: hidden;
}

canvas {
    background-image: radial-gradient(#666, #333);
}

#instructions {
    position: absolute;
    color: #fff;
    bottom: 0;
    padding-bottom: 6px;
    font-family: sans-serif;
    width: 100%;
    text-align: center;
    pointer-events: none;
}